Composite plastic display cover

ABSTRACT

Methods for manufacturing a composite plastic display cover include defining an edge portion of a base plastic cover sheet. A strengthening treatment is applied to the edge portion of the base plastic cover sheet to improve mechanical strength. A hardening treatment is applied to the base plastic cover sheet and over the strengthening treatment to improve anti-glare and anti-scratch properties.

BACKGROUND

1. Field of the Disclosure

This disclosure relates generally to information handling systems and,more particularly, to a composite plastic display cover for informationhandling systems.

2. Description of the Related Art

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option available to users is information handling systems. Aninformation handling system generally processes, compiles, stores,and/or communicates information or data for business, personal, or otherpurposes thereby allowing users to take advantage of the value of theinformation. Because technology and information handling needs andrequirements vary between different users or applications, informationhandling systems may also vary regarding what information is handled,how the information is handled, how much information is processed,stored, or communicated, and how quickly and efficiently the informationmay be processed, stored, or communicated. The variations in informationhandling systems allow for information handling systems to be general orconfigured for a specific user or specific use such as financialtransaction processing, airline reservations, enterprise data storage,or global communications. In addition, information handling systems mayinclude a variety of hardware and software components that may beconfigured to process, store, and communicate information and mayinclude one or more computer systems, data storage systems, andnetworking systems.

Advancements in packaging design have reduced both the weight andthickness of information handling systems. In particular, componentsincluded in displays of portable information handling systems, such aslaptops, notebooks, and tablet form factors, are the object of effortsto reduce weight and thickness, without compromising structuralstrength. Specifically, display covers are rapidly becoming a primaryinterface between a user and a portable information handling system.Often referred to as a ‘cover glass’ because of the glass base materialused, display covers are also subject to optical performance attributes,such as supporting high resolution displays, high brightness, excellentcolor reproduction, as well as supporting touch functionality.

As overall weight of portable information handling systems decreases,the weight contribution of display covers made of glass has come underincreased scrutiny by product designers. Although reducing the thicknessof a display cover made of glass will reduce weight, an undesirablereduction in structural rigidity may also occur with thinner displaycovers. Additionally, newer designs of information handling systemsinvolving integration of various user interface elements are appearingand are affecting display cover performance. Display covers may nowinclude features such as color bezels, protrusions, holes, or othermounting structures for buttons or other electronic devices, such ascameras and microphones. Such features may introduce localized stressconcentrations that may lead to undesirable early failure of displaycovers, often in the form of cracks or fractures.

Accordingly, it is desirable to have an improved design and acorrespondingly improved manufacturing method for display covers in aninformation handling system that yields lightweight yet sufficientlyrobust display covers.

SUMMARY

In one aspect, a disclosed method is for manufacturing a compositeplastic display cover for use in an information handling system. Themethod may include applying a strengthening treatment to an edge portionof a base plastic cover sheet, the base plastic cover sheetcorresponding in size to the composite plastic display cover and havinga center portion, including applying a polymeric composite coating tothe edge portion. After applying the strengthening treatment, the methodmay include applying a hardening treatment to the base plastic coverincluding applying a nanoceramic solgel. The method may include dryingthe nanoceramic solgel, and thermally treating the dried nanoceramicsolgel to form a silica layer at an external surface of the compositeplastic display cover.

Other disclosed aspects include a composite plastic display cover foruse in an information handling system, a display having the compositeplastic display cover, and an information handling system including adisplay having the composite plastic display cover.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and itsfeatures and advantages, reference is now made to the followingdescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a block diagram of selected elements of an embodiment of aninformation handling system;

FIG. 2 is a block diagram of selected elements of an embodiment of aplastic display cover; and

FIG. 3 is flowchart depicting selected elements of an embodiment of amethod for manufacturing a composite plastic display cover for use in aninformation handling system.

DESCRIPTION OF PARTICULAR EMBODIMENT(S)

In the following description, details are set forth by way of example tofacilitate discussion of the disclosed subject matter. It should beapparent to a person of ordinary skill in the field, however, that thedisclosed embodiments are exemplary and not exhaustive of all possibleembodiments.

For the purposes of this disclosure, an information handling system mayinclude an instrumentality or aggregate of instrumentalities operable tocompute, classify, process, transmit, receive, retrieve, originate,switch, store, display, manifest, detect, record, reproduce, handle, orutilize various forms of information, intelligence, or data forbusiness, scientific, control, entertainment, or other purposes. Forexample, an information handling system may be a personal computer, aPDA, a consumer electronic device, a network storage device, or anothersuitable device and may vary in size, shape, performance, functionality,and price. The information handling system may include memory, one ormore processing resources such as a central processing unit (CPU) orhardware or software control logic. Additional components or theinformation handling system may include one or more storage devices, oneor more communications ports for communicating with external devices aswell as various input and output (I/O) devices, such as a keyboard, amouse, and a video display. The information handling system may alsoinclude one or more buses operable to transmit communication between thevarious hardware components.

For the purposes of this disclosure, computer-readable media may includean instrumentality or aggregation of instrumentalities that may retaindata and/or instructions for a period of time. Computer-readable mediamay include, without limitation, storage media such as a direct accessstorage device (e.g., a hard disk drive or floppy disk), a sequentialaccess storage device (e.g., a tape disk drive), compact disk, CD-ROM,DVD, random access memory (RAM), read-only memory (ROM), electricallyerasable programmable read-only memory (EEPROM), and/or flash memory(SSD); as well as communications media such wires, optical fibers,microwaves, radio waves, and other electromagnetic and/or opticalcarriers; and/or any combination of the foregoing.

As noted previously, current information handling systems may demandever thinner and lighter products, without sacrificing strength andstability. In particular, thinner displays are being developed forportable information handling systems that include a display cover. Aswill be described in further detail, the inventors of the presentdisclosure have developed novel methods and structures disclosed hereinfor manufacturing a composite plastic display cover having astrengthened edge portion and a hardened external surface. The disclosedcomposite plastic display cover is thin and lightweight, while meetingexpectations for durability and high quality.

Particular embodiments are best understood by reference to FIGS. 1, 2,and 3 wherein like numbers are used to indicate like and correspondingparts.

Turning now to the drawings, FIG. 1 illustrates a block diagramdepicting selected elements of an embodiment of information handlingsystem 100. As shown in FIG. 1, components of information handlingsystem 100 may include, but are not limited to, processor subsystem 120,which may comprise one or more processors, and system bus 121 thatcommunicatively couples various system components to processor subsystem120 including, for example, a memory subsystem 130, an I/O subsystem140, local storage resource 150, and a network interface 160. System bus121 may represent a variety of suitable types of bus structures, e.g., amemory bus, a peripheral bus, or a local bus using various busarchitectures in selected embodiments. For example, such architecturesmay include, but are not limited to, Micro Channel Architecture (MCA)bus, Industry Standard Architecture (ISA) bus, Enhanced ISA (EISA) bus,Peripheral Component Interconnect (PCI) bus, PCI-Express bus,HyperTransport (HT) bus, and Video Electronics Standards Association(VESA) local bus.

In FIG. 1, network interface 160 may be a suitable system, apparatus, ordevice operable to serve as an interface between information handlingsystem 100 and a network 155. Network interface 160 may enableinformation handling system 100 to communicate over network 155 using asuitable transmission protocol and/or standard, including, but notlimited to, transmission protocols and/or standards enumerated belowwith respect to the discussion of network 155. In some embodiments,network interface 160 may be communicatively coupled via network 155 tonetwork storage resource 170. Network 155 may be implemented as, or maybe a part of, a storage area network (SAN), personal area network (PAN),local area network (LAN), a metropolitan area network (MAN), a wide areanetwork (WAN), a wireless local area network (WLAN), a virtual privatenetwork (VPN), an intranet, the Internet or another appropriatearchitecture or system that facilitates the communication of signals,data and/or messages (generally referred to as data). Network 155 maytransmit data using a desired storage and/or communication protocol,including, but not limited to, Fibre Channel, Frame Relay, AsynchronousTransfer Mode (ATM), Internet protocol (IP), other packet-basedprotocol, small computer system interface (SCSI), Internet SCSI (iSCSI),Serial Attached SCSI (SAS) or another transport that operates with theSCSI protocol, advanced technology attachment (ATA), serial ATA (SATA),advanced technology attachment packet interface (ATAPI), serial storagearchitecture (SSA), integrated drive electronics (IDE), and/or anycombination thereof. Network 155 and its various components may beimplemented using hardware, software, or any combination thereof.

As depicted in FIG. 1, processor subsystem 120 may comprise a system,device, or apparatus operable to interpret and/or execute programinstructions and/or process data, and may include a microprocessor,microcontroller, digital signal processor (DSP), application specificintegrated circuit (ASIC), or another digital or analog circuitryconfigured to interpret and/or execute program instructions and/orprocess data. In some embodiments, processor subsystem 120 may interpretand/or execute program instructions and/or process data stored locally(e.g., in memory subsystem 130 and/or another component of physicalhardware 102). In the same or alternative embodiments, processorsubsystem 120 may interpret and/or execute program instructions and/orprocess data stored remotely (e.g., in network storage resource 170).

Also in FIG. 1, memory subsystem 130 may comprise a system, device, orapparatus operable to retain and/or retrieve program instructions and/ordata for a period of time (e.g., computer-readable media). Memorysubsystem 130 may comprise random access memory (RAM), electricallyerasable programmable read-only memory (EEPROM), a PCMCIA card, flashmemory, magnetic storage, opto-magnetic storage, and/or a suitableselection and/or array of volatile or non-volatile memory that retainsdata after power to its associated information handling system, such assystem 100, is powered down. Local storage resource 150 may comprisecomputer-readable media (e.g., hard disk drive, floppy disk drive,CD-ROM, and/or other type of rotating storage media, flash memory,EEPROM, and/or another type of solid state storage media) and may begenerally operable to store instructions and/or data. Likewise, networkstorage resource 170 may comprise computer-readable media (e.g., harddisk drive, floppy disk drive, CD-ROM, and/or other type of rotatingstorage media, flash memory, EEPROM, and/or other type of solid statestorage media) and may be generally operable to store instructionsand/or data. In system 100, I/O subsystem 140 may comprise a system,device, or apparatus generally operable to receive and/or transmit datato/from/within system 100. I/O subsystem 140 may represent, for example,a variety of communication interfaces, graphics interfaces, videointerfaces, user input interfaces, and/or peripheral interfaces. Asshown, I/O subsystem 140 may comprise touch panel 142 and displayadapter 144. Touch panel 142 may include circuitry for enabling touchfunctionality in conjunction with display 146 that is driven by displayadapter 144. As shown, display 146 may include a composite plasticdisplay cover, as described herein.

Turning now to FIG. 2, selected elements of an embodiment of compositeplastic display cover 200 are illustrated. As shown, composite plasticdisplay cover 200 may represent various embodiments of composite plasticdisplay covers described herein. Composite plastic display cover 200includes edge portion 204, which may be a band at an exterior edge. Edgeportion 204 may extend around edges of composite plastic display cover200 and may cover both faces. Composite plastic display cover 200includes center portion 202, which may represent a display portionthrough which a user views a display that composite plastic cover 200 isattached to. Center portion 202 may represent both faces of compositeplastic display cover 200.

As a result of the various desirable characteristics of a display cover,as described above, composite plastic display cover 200 may be formedusing a base plastic cover sheet that is strengthened in a specificmanner. In particular, edge portion 204 may be subject to astrengthening treatment involving application of a strengthening layer.Because edge portion 204 is not normally visible to a user and does notrepresent the display portion, strengthening treatments used at edgeportion 204 may not have the same optical properties as other treatmentsused. After the strengthening treatment is performed, a hardeningtreatment involving application of a hardening layer over an entireexterior surface of composite plastic display cover 200 may beperformed. The hardening treatment may apply materials with desiredoptical properties for high quality display performance. The hardeningtreatment may compensate for an otherwise lower than desirable hardnessof the base plastic cover sheet, and may increase surface hardness ofcomposite plastic display cover accordingly. After the hardeningtreatment, a hardness of center portion 202 may be higher, orsubstantially higher, than edge portion 204. The hardness is measured ata surface of composite plastic display cover 200. Specifically, afterthe hardening treatment is applied, the hardness of edge portion 204 maybe about 3-4 H, where H is a hardness value according to the Mohs scaleof mineral hardness, while the hardness of center portion 202 may beabout 6-8 H. The reduced hardness of edge portion 204 may arise from thestrengthening layer, which may add strength but may reduce hardness orstiffness. The higher hardness of center portion 202 may result inexcellent anti-scratch properties of the hardening layer, which isdesirable.

Manufacture of composite plastic display cover 200 may involve differentsteps, in particular embodiments. First the base plastic cover sheet maybe cut to a final size corresponding to composite plastic display cover200. The base plastic cover sheet may be made of a suitable polymermaterial, such as polyethylene terephthalate (PET). In some embodiments,the base plastic cover sheet is itself a plastic-glass composite, forexample, including alternating plastic and glass layers.

Then, the strengthening treatment may be applied to edge portion 204.For purposes of the strengthening treatment, center portion 202 may bemasked to expose only edge portion 204. A polymeric composite coatingmay be applied to edge portion 204. The polymeric composite coating maybe diffused or laminated onto edge portion 204 of the base plastic coversheet. The polymeric composite coating may include with differentpolymer formulations for specific desired properties. The polymericcomposite coating may include at least one of: polyurethane (PU),polyetherimide (PEI), impact-modified poly(methyl methacrylate) (PMMA),polycarbonate (PC), polyvinylpyrrolidine (PVP), and glycol-modifiedpolyethylene terephthalate (PET-G). For example, to obtain desiredanti-fog properties, polyvinylpyrrolidine may be used. In other example,to obtain improvement of adhesion to zirconia, glycol-modifiedpolyethylene terephthalate may be used. The polyurethane polymer may bediffused with particulate or filler, such as silica fiber, silicaparticles, ceramic fiber, or ceramic particles. In certain embodiments,edge portion 204 may be further laminated with a carbon fiber layer toimprove strength. In some embodiments, edge portion 204 includes PEIwith surface-modified sepiolite nanofibers. In particular embodimentsedge portion 204 includes PC that is reinforced with vapor-grown carbonnanofibers that are laser infused at about 20% composition by volume,which may impart a degree of surface conductivity to edge portion 204.

In some embodiments, edge portion 204 is diffused with a colorant toform a bezel for decorative or ornamental purposes. The colorant may beprovide at least a certain amount of opacity to edge portion 204. Thecolorant may be laser infused where laser energy is used to promotediffusion of the colorant into edge portion 204 at a low temperaturenear a softening temperature of the base plastic cover sheed. Laserinfusion may result in a highly uniform surface with specificallydesired gloss values. The strengthening treatment may include applyingan anti-microbial layer to edge portion 204, which may come into directcontact with a user or the environment.

After the strengthening treatment, the hardening treatment may beapplied. In certain embodiments, the hardening layer includes ananoceramic and is applied to the exterior surface of the base plasticcover sheet, including over the strengthening layer. Thus, the hardeninglayer may encapsulate the strengthening layer, at least to a certainextent. In some embodiments, the hardening layer may comprise twodifferent layers. A first ultrathin hardening layer (about 10-20 nm) maybe vapor deposited over edge portion 204 and center portion 202. Thefirst ultrathin layer may be vapor deposited silica or a vaporcodeposited metal-silica mixture. Then, a second hardening layer may beapplied to center portion 202. The second hardening layer may be appliedas a nanoceramic solgel. The hardening layer may be about 100-500 nm inoverall thickness. The thickness of the hardening layer may depend uponan overall size of composite plastic display cover 200. For example,when a diagonal of composite plastic display cover 200 is about 13inches or less, a very thin hardening layer of about 100 nm overallthickness may be applied. When the diagonal of composite plastic displaycover 200 is greater than about 13″, thicker hardness layer coatings maybe applied.

The nanoceramic solgel may include alumina, silica, or zirconia that isapplied in solution form using an aqueous or alcoholic solvent, which isdried away to leave the nanoceramic hardening layer. The nanoceramic maythen be subject to a thermal treatment to form a solid film.Alternatively or additionally, the hardening layer may be vapordeposited onto the base plastic cover. The resulting hardening layer orlayers may provide anti-glare and anti-scratch properties that aredesirable for composite plastic display cover 200. In certainembodiments the solgel is selected from: LUDOX (E.I. duPont de Nemoursand Co., Inc., Wilmington Del.) and NYACOL (Nyacol Co., Ashland Mass.).

In one embodiment, zirconia solgel functionalized withtrimethylethoxysilane (TMES) is used for the nanoceramic solgel.Zirconia may act as both a coupling agent and as a C=C provider, whileTMES may prevent particle aggregation and may increase hydrophobicity ofthe hardening layer. The TMES-functionalized zirconia particles may beUV-cured together with a monomer (2-hydroxyethyl methacrylate (2-HEMA))and a crosslinking agent (dipentaerythritol hexaacrylate (DPHA)) to formhighly transparent hard coatings on plastic PET with surface hardness of6 H. The hardness of the nanoceramic applied as a solgel to form thehardening layer may be controlled by varying particle loading and UVintensity used for curing. In particular embodiments, the base plasticcover sheet is about 0.5 mm thick and the hardening layer is about100-500 nm thick.

In particular embodiments, increased thermal conductivity of edgeportion 204 is desirable, for example, when display electronics in closeproximity to composite plastic display cover 200 generate substantialamounts of heat to be dissipated. In such instances, the hardening layermay be formed with a thermally conductive material at edge portion 204where the hardening layer covers the strengthening layer. In oneembodiment, Si₃N₄—Si₂N₂O—Y₂Si₂O₇ may be used where silica is thenanoceramic. In various embodiments, conductive ceramics having thermalconductivity greater than about 100 MW/mK and elastic moduli greaterthan about 300 GPa, such as AlN and SiC may be used where high hardnessis desired with increased thermal conductivity.

Referring now to FIG. 3, a block diagram of selected elements of anembodiment of method 300 for manufacturing a composite plastic displaycover for use in an information handling system (such as informationhandling systems 100) is depicted in flowchart form. It is noted thatcertain operations described in method 300 may be optional or may berearranged in different embodiments.

Method 300 may begin by applying a strengthening treatment (operation302) an edge portion of a base plastic cover sheet corresponding in sizeto a composite plastic display cover and having a center portion,including applying a polymeric composite coating to the edge portion. Ahardening treatment may be applied (operation 304) to the base plasticcover including applying a nanoceramic solgel. The nanoceramic solgelmay be dried (operation 306). The dried nanoceramic solgel may bethermally treated (operation 308) to form a scratch-resistant layer atan external surface of the composite plastic display cover.

As disclosed herein, methods for manufacturing a composite plasticdisplay cover include defining an edge portion of a base plastic coversheet. A strengthening treatment is applied to the edge portion of thebase plastic cover sheet to improve mechanical strength. A hardeningtreatment is applied to the base plastic cover sheet and over thestrengthening treatment to improve anti-glare and anti-scratchproperties.

The above disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments which fall within thetrue spirit and scope of the present disclosure. Thus, to the maximumextent allowed by law, the scope of the present disclosure is to bedetermined by the broadest permissible interpretation of the followingclaims and their equivalents, and shall not be restricted or limited bythe foregoing detailed description.

What is claimed is:
 1. A method of manufacturing a composite plasticdisplay cover for use in an information handling system, the methodcomprising: applying a strengthening treatment to an edge portion of abase plastic cover sheet, the base plastic cover sheet corresponding insize to the composite plastic display cover and having a center portion,including applying a polymeric composite coating to the edge portion;after applying the strengthening treatment, applying a hardeningtreatment to the base plastic cover sheet including applying ananoceramic solgel; drying the nanoceramic solgel; and thermallytreating the dried nanoceramic solgel to form a scratch-resistant layerat an external surface of the composite plastic display cover.
 2. Themethod of claim 1, wherein the strengthening treatment includes: addinga particulate to the polymeric composite coating selected from at leastone of: silica fiber, silica particles, ceramic fiber, and ceramicparticles.
 3. The method of claim 1, wherein the strengthening treatmentincludes: laminating a carbon fiber layer to the edge portion.
 4. Themethod of claim 1, wherein the strengthening treatment includes:diffusing a colorant into the edge portion.
 5. The method of claim 4,wherein the colorant is at least partially opaque, and wherein diffusingthe colorant includes laser-infusing the colorant.
 6. The method ofclaim 1, wherein the polymeric composite coating includes at least oneof: polyurethane, polyetherimide, impact-modified poly(methylmethacrylate), polycarbonate, polyvinylpyrrolidine, and glycol-modifiedpolyethylene terephthalate.
 7. The method of claim 1, wherein applyingthe strengthening treatment includes: applying an anti-microbial coatingto the edge portion.
 8. The method of claim 1, wherein the nanoceramicsolgel includes at least one of: silica, alumina, and zirconia.
 9. Themethod of claim 1, wherein the strengthening treatment includes:vapor-depositing silica to the base plastic cover.
 10. The method ofclaim 1, wherein the base plastic cover sheet comprises a composite ofplastic and glass layers corresponding in size to the composite plasticdisplay cover.
 11. The method of claim 1, wherein applying the hardeningtreatment results in a lower hardness at the edge portion and a higherhardness at the center portion.
 12. The method of claim 1, whereinapplying the hardening treatment includes: prior to applying thenanoceramic solgel, vapor depositing a nanolayer of silica to both theedge portion and the center portion; and applying the nanoceramic solgelto the center portion over the nanolayer of silica.
 13. The method ofclaim 12, wherein vapor depositing the nanolayer of silica includes:vapor codepositing a metal with the silica to form a nanolayer of asilica-metal mixture.
 14. A composite plastic display cover for use inan information handling system, comprising: a base plastic cover sheetthat corresponds in size to the composite plastic display cover, thebase plastic cover sheet including an edge portion and a center portiondefined therein; a strengthening layer applied to the edge portion, thestrengthening layer including a polymeric composite coating; and ahardening layer applied to the base plastic cover sheet, the hardeninglayer including a nanoceramic layer.
 15. The composite plastic displaycover of claim 14, wherein the strengthening layer includes: aparticulate selected from at least one of: silica fiber, silicaparticles, ceramic fiber, and ceramic particles.
 16. The compositeplastic display cover of claim 14, wherein the strengthening layerincludes: a carbon fiber layer over the edge portion.
 17. The compositeplastic display cover of claim 14, wherein the strengthening layerincludes: a colorant diffused into the edge portion.
 18. The compositeplastic display cover of claim 14, wherein the colorant is at leastpartially opaque, and wherein diffusing the colorant includeslaser-infusing the colorant.
 19. The composite plastic display cover ofclaim 14, wherein the polymeric composite coating includes at least oneof: polyurethane, polyetherimide, impact-modified poly(methylmethacrylate), polycarbonate, polyvinylpyrrolidine, and glycol-modifiedpolyethylene terephthalate.
 20. The composite plastic display cover ofclaim 14, wherein strengthening layer includes: an anti-microbialcoating at the edge portion.
 21. The composite plastic display cover ofclaim 14, wherein the nanoceramic solgel includes at least one of:silica, alumina, and zirconia.
 22. The composite plastic display coverof claim 14, wherein the strengthening layer includes vapor-depositedsilica.
 23. The composite plastic display cover of claim 14, wherein thebase plastic cover sheet comprises a composite of plastic and glasslayers corresponding in size to the composite plastic display cover. 24.The composite plastic display cover of claim 14, wherein the compositeplastic display cover has a lower hardness at the edge portion and ahigher hardness at the center portion.
 25. The composite plastic displaycover of claim 14, wherein the hardening layer includes: a vapordeposited nanolayer of silica at both the edge portion and the centerportion; and the nanoceramic solgel at the center portion over thenanolayer of silica.
 26. The composite plastic display cover of claim25, wherein the nanolayer of silica includes: a vapor codepositedsilica-metal mixture.